Ethylene di(acetate)

Endpoint summary

Additional information

There are no data available for the biodegradation of ethylene diacetate (CAS 111-55-7). In order to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from one structurally related substance was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

 

Environmental fate parameters of the target substance ethylene diacetate (CAS 111-55-7) and the source substance 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate (CAS 111-21-7) are presented in the following table.

	Target substance	Source substance
CAS	111-55-7	111-21-7
Chemical Name	ethylene diacetate	2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate
Molecular weight	146.14	234.25
Water solubility	171.1 g/L	> 1000 mg/L
Type of glycol	Ethylene glycol	Triethylene glycol
Type of carboxylic acid	Acetic acid	Acetic acid
Phototransformation in air	34.13 h (24 h day)	12.112 h (24 h day)
Hydrolysis	DT50 > 12 h, pH 7	DT50 > 12 h, pH 7
Biodegradation: screening tests	RA: CAS 111-21-7 Readily biodegradable (RL4 data + QSAR)	Readily biodegradable
Bioaccumulation	Waiving; log Kow < 3	Waiving; log Kow < 3
Adsorption/Desorption	log Koc: 1 (MCI); 0.85 (estimation based on log Kow)	log Koc: 1 (MCI); 0.53 (estimation based on log Kow)
Henry’s Law constant	< 1 Pa m³/mole	< 1 Pa m³/mole

 

The above mentioned substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information is used to predict the same endpoints for ethylene diacetate. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

 

The target substance ethylene diacetate (CAS 111-55-7) and the source substance 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate (CAS 111-21-7) are characterized by a similar environmental behaviour based on the relevant physico/chemical and environmental fate properties. 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate is considered to be readily biodegradable in view of the results of one experimental study conducted according to OECD 301C (60% based on O2 consumption after 28 d). The read-across substance is characterized by a similar alcohol component (triethylene glycol compared to ethylene glycol) diesterified with acetic acid. Since the potential for biodegradation is expected to decrease at longer C-chain lengths, the source substance containing triethylene glycol can be regarded as a worst-case read-across substance for the target substance. Therefore, ethylene diacetate is considered to be readily biodegradable. This is also supported by additional published data and (Q)SAR calculation.

The degradation via abiotic hydrolysis is not considered to be a relevant degradation pathway in the environment since QSAR results using HYDROWIN v2.00 resulted in DT50 values > 12 h at pH 7. Considering the high water solubility (171.1 g/L for the target, and > 1000 g/L for the source substance) and the low potential for adsorption to organic soil and sediment particles (log Koc values: < 3, KOCWIN v2.00), the main compartment for environmental distribution is expected to be the surface water for both, the source and target substance. Nevertheless, persistency in this compartment is not expected since they are considered to be readily biodegradable and will be therefore rapidly and ultimately degraded in sewage treatment plants (Guidance on information requirements and chemical safety assessment, Chapter R.7b (ECHA, 2017)). Evaporation into air and the transport through the atmospheric compartment is not expected to be a relevant pathway for the target and the source substance based on the low evaporation potential indicated by a low Henry’s Law constant (< 1 Pa m³/mole (HENRYWIN v3.20)) and vapour pressure (22.68 Pa at 20°C; SPARC v4.5). Accumulation in air and the subsequent transport to other environmental compartments is not likely to occur at a significant degree. However, if released into air, the substances are susceptible to indirect photodegradation by OH-radicals with a DT50 of 34.13 h for the target substance and 12.11 h for the source substance (AOPWIN v1.92). The potential for bioaccumulation is assumed to be low based on log Kow values < 3.

In conclusion both substances show a similar environmental fate and behavior.As it can be seen in the data matrix of the analogue justification in IUCLID Section 13, all reliable physico/chemical and environmental fate data from the target and the source substance support this assessment.The read-across for the biodegradation endpoint can be seen as a worst case since the source substance is characterized by a longer alcohol chain (triethylene glycol compared to ethylene glycol) which is the determining factor for biodegradation.